A year of snollygosters, jeggings and tweetups marked the end of the 21st century's first decade, according to word enthusiasts who have spent Christmas burrowing into Britain's biggest linguistic database.

The three words lead the list of hundreds of new English coinings in the Oxford English Dictionary in the last 12 months, along with novel uses for familiar words, such as simples, unfriend and zombie banking.

"It has been another rich year," said Susie Dent, the lexicographic specialist from the TV show Countdown, who led the comprehensive scanning of more than 2bn words. "Last year, we found that 'credit crunch' was the most familiar new word, and the effect of the recession has stayed with us through 2009."

Staycation – a money-saving holiday in the UK – is an example, an elision of words that caught on immediately. The zombie bankers are only one of a rich vocabulary from the fallout of the City's near-meltdown: paywalls, freemiums (free service providers with paid-for premium extras) and bossnapping, to oppose sackings or pay cuts, are other popular newcomers.

The overwhelming influence of the internet also continued unbridled, with unfriend coming from the practice of dropping a contact from a Facebook site. Voted the word of the year by the New Oxford American Dictionary, it shares the honours in the UK with the alternative defriend, which is nearly as widely used.

Tweetup has prospered via the more friendly social networking practice of organising gatherings through Twitter, using the rhyme with "meet" in the traditional way of creators of new words. Simples, meanwhile, comes from an older-fashioned source.

"It appeared on the 'compare the meerkat' TV adverts for insurance and quickly become a catchphrase said by anyone [to] mean something very easy to achieve," said Dent. "It really seems to have captured the public's imagination in 2009."

Jeggings, another top scorer in usage terms, comes from the traditional word-marrying school of new terms – mixing jeans and leggings to describe new clothing style. Snollygosters, meaning "shrewd, unprincipled people", is actually an old word revived: first recorded in 1855, it fell into obscurity until the first stirrings of election fever in the early autumn.

The survey also notes new words in overseas English, including hatinator (hat and fascinator) to describe the latest headwear craze in Australia, and hohum, a New Zealand coining for those who prefer to observe rather than act.